a, Immunostaining of ACP neurons in the rostral Amb of a neonatal (postnatal day 2) mouse. ACP neurons stained positive for calbindin (red) and stained weakly positive for BChE (cyan). b, Immunostaining of neonatal ACV neurons in the caudal Amb of a postnatal day 2 mouse. ACV neurons stained positive for BChE and negative for calbindin. Bars, 20 μm. c, Map of ACP and ACV neurons in neonatal Amb. Sagittal schematic view showing overlay of soma of all neurons (circles) across all sections spanning a single neonatal (postnatal day 2) Amb that was stained for ACP marker calbindin (dark blue circles) and ACV marker BChE (light blue circles). d, Quantification of absolute numbers of ACP neurons (calbindin+, dark blue) and ACV neurons (BChE+, light blue) per Amb in neonatal mice (mean ± s.d., n = 3 mice). e, Immunostaining of ACP neurons in the rostral Amb of an adult (postnatal day 60) mouse. ACP neurons stained positive for calbindin (red) and stained weakly positive for BChE (cyan). f, Immunostaining of adult ACV neurons in the caudal Amb of a postnatal day 60 mouse. ACV neurons stained positive for BChE and negative for calbindin. Bars, 20 μm. g, Map of ACP and ACV neurons in adult Amb. Sagittal schematic view showing overlay of soma of all neurons (circles) across all sections spanning a single adult (postnatal day 60) Amb that was stained for calbindin (dark blue) and BChE (light blue). Note similarity in marker expression and cell type distribution in neonatal and adult Amb. h, Quantification of absolute numbers of ACP neurons (calbindin+, dark blue) and ACV neurons (BChE+, light blue) per Amb in adult mice (mean ± s.d., n = 3 mice).